So, bought this one ahead of Poland this year, as my previous bento box was extremely fiddly to mount and operate, especially that I have cables sticking out of the top of my frame, so strapping it around the head tube is a bit of a no-go.

The Stealth Pocket 400 (vs. other models) was, on the other hand, designed with this type of frame in mind, and it does the trick just fine. Here's what it looks like:

It's got rubbery bottom (steady on Kev), so doesn't slide on the frame. And - importantly - it has built in plastic "walls" on the inside, so it's stiff too, which makes putting things in and taking them out pretty easy (I did say, steady on ).